So how frequently does he have sex on his mind?

This imbalance implies that we ought to assume guys to be a lot more motivated to have intercourse, says Dr Fleischman, and girls to be choosy about their partner. It’s one thing we discover elsewhere in the animal kingdom – and, intriguingly, when the parental roles are reversed, so are sexual habits. “Male sea horses get pregnant, for example. And they have a tendency to be choosy, since they bear the larger cost.”

And it is not a Just So story, which evolutionary psychology is sometimes accused of. In a single review of the literature, “not one particular review located that ladies consider about intercourse much more than guys,” says Dr Fleischman. One trial, published in the Journal of Sex Study, located that males think about intercourse – on typical – 34 occasions a day, in contrast with women’s 19. Dr Fleischman mentions yet another that put the figures a lot reduced – about once a day for males, when every a number of days for females – but regularly, the findings are that males believe about sex far more than women do. “Men have more intrusive thoughts, also – it’s more difficult for them to ignore ideas about sex,” she says.

It’s not just pondering about it. Typically, men’s sexual activity is constrained by how often girls will consent to sex – but there is a normal experiment that shows what would take place if it was restricted by how usually males consent. That normal experiment is, of program, the lifestyles of gay guys. “If you seem at gay guys and girls,” says Fleischman, “you’ll see that gay guys have a lot more partners than gay females do.” Having to gain consent from a guy is a far reduced bar to clear, she says, than gaining consent from a female.

This could be since of some basic distinction amongst gay guys and straight males, other than their sexual preference – but it doesn’t seem to be to be. “If you have two men, and they have the very same intercourse drive, but one particular is constrained in how considerably sex he has by guys, and the other is limited by women, one is going to have a lot more intercourse than the other,” says Fleischman, adding with a laugh: “My boyfriend always says, ‘I wish I was gay. It’d be so significantly easier’.”

It appears, then, that the “sex-mad man” and “cuddle-hungry woman” stereotypes are broadly accurate.

And so they are – but we must be cautious with them. Stereotypes are helpful since they typically give us great data about groups, says Prof Nicholas Epley, a University of Chicago psychologist and writer of Mindwise: How we recognize what other folks consider, feel, feel and want. “You’ve learnt that tigers are harmful,” he says. “You see a tiger, you’d be rightly scared, even though this specific tiger may well not assault you. If you see a beaver, you are not. Your stereotypes of tigers and beavers are operating admirably in that predicament.”

Our stereotypes of groups of men and women generally level us in the correct direction as properly. “We find out items about groups of people. We discover issues about conservatives and liberals, and football players and professors, and males and females,” says Prof Epley, and individuals factors are usually, broadly, right. These stereotypes are about what separates groups, not what unites them.

“The stereotypes are about the factors that make men and women apparently diverse from each other. A single is a lot more interdependent, 1 is much more independent. 1 is a lot more sociable, the other a lot more competitive.” And one particular is more sexually rapacious than the other.

But focusing on the distinctions exaggerates individuals differences. All of the over stereotypes have a degree of truth – but the result is far much less pronounced than we picture it to be. For instance, the review pointed out over found that guys think about intercourse 34 instances a day. That is really a good deal – about twice every single waking hour. But it is not every single 7 seconds, as myth has it, and girls apparently consider about it rather often themselves. And, as Prof Epley factors out, the groups “men” and “women” will overlap. Dr Fleischman agrees: “The guys who consider about intercourse the least will feel about intercourse much less than the girls who think about sex the most.”

And, yet again, it is not just thinking about it. There are plenty of scenarios in which females may seek out casual intercourse, or sex outside their partnership, “maybe to get far better genes than their mate has, or maybe to get standing, or perhaps to get resources”, says Dr Fleischman. (I must anxiety that this is not a conscious factor we’re talking about evolutionarily productive methods, not deliberate calculation.) It’s certainly difficult to get great statistics on how often men and women cheat on their spouses, but evidence of human infidelity can be identified in one more, unexpected place: gorilla testicles.

Male gorillas have modest testes, since even however they have massive harems of females, people females only mate with one particular male, so there is no “sperm competition”. Chimpanzee females, by contrast, mate with a number of males in their group when receptive, and males have quite huge testes, so that they can get much more sperm into every female and maximise their chances of currently being a father. “Human males have testes smaller sized than individuals of chimps, which prospects folks to say we’re less promiscuous than chimps, which is correct,” says Dr Fleischman – but our testes are much more substantial than people of a gorilla.

Equally, there are plenty of scenarios in which it tends to make evolutionary sense for guys to be less intercourse-obsessed: “If you are a smaller sized male, the very best approach may well be for you to be a good dad. In general, it’s a lot more adaptive for males to be motivated for sex, and for girls to be much more coy, but the stereotype is definitely overstated,” Dr Fleischman says.

Jon Snow may possibly be correct, to an extent – several men most likely do feel about intercourse with each lady they meet, and most men feel about sex far more than most girls. But the variation among the sexes is less than we envision. If we assume that each man we meet is intercourse-mad and every lady uninterested, then we’ll get it wrong with embarrassing regularity.

We could consider men are from Mars and women are from Venus, but as Prof Epley puts it: “The reality is much more like men are from Iowa and ladies are from Illinois.”

So how frequently does he have sex on his mind?